Pneumatic rotary motor without connecting rods

ABSTRACT

A pneumatic rotary motor includes cylinders around a central channel, an inlet tube, an exhaust tube, ducts being in communication with the cylinders, a rotor in the channel and including an eccentric rotation member, a rotating shaft, an intake valve adapted to communicate the inlet tube with the duct or not, and an exhaust valve adapted to communicate the exhaust tube with the duct or not, and pistons slidably mounted in the cylinders and being in contact with the rotation member. Sequentially entering compressed air into each cylinder through the inlet tube, the intake valve, and the duct will push the piston to rotate the rotation member to output power from the rotating shaft, and release the air from one of the cylinders through the duct, the exhaust valve, and the exhaust tube at the end of each revolution of the rotor.

BACKGROUND OF THE INVENTION

1. Field of Invention

The invention relates to pneumatic motors and more particularly to a pneumatic rotary motor without connecting rods and other associated components.

2. Related Art

Conventionally, a pneumatic motor can convert energy of compressed air into mechanical motion. There have been numerous suggestions in prior patents for pneumatic motor. However, such prior art pneumatic motors are typically relatively complex in constructions due to the increased number of connecting rods and unreliable in use. Thus, the need for improvement still exists.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a pneumatic rotary motor without any connecting rods so as to increase transmission efficiency, decrease the manufacturing cost, and make maintenance easy.

To achieve the above and other objects, the present invention provides a pneumatic rotary motor comprising a housing including a central, cylindrical channel, a plurality of cylinders equally spaced around a periphery of the channel and in communication therewith, an inlet tube, an exhaust tube, and a plurality of ducts each being in communication with the cylinder; a rotor fitted in the channel and including an eccentric rotation member on a top, a lower rotating shaft operatively connected to the rotation member, an intermediate intake valve adapted to communicate the inlet tube with the duct or not, and an exhaust valve adapted to communicate the exhaust tube with the duct or not; a plurality of pistons each slidably mounted in the cylinder and being in contact with the rotation member; and a plurality of cylinder head covers each releasably secured to an outer portion of the cylinder; whereby sequentially entering compressed air into each of the cylinders through the inlet tube, the intake valve, and the duct will push the piston to rotate the rotation member to output power from the rotating shaft, and release the air from one of the cylinders through the duct, the exhaust valve, and the exhaust tube at the end of each revolution of the rotor.

In one aspect of the present invention the number of each of the cylinders, the pistons, and the ducts is three, and thus a phase difference of 120 degrees exists between the compressed air entering one cylinder and the compressed air entering the next cylinder.

In another aspect of the present invention the number of each of the cylinders, the pistons, and the ducts is five, and thus a phase difference of 72 degrees exists between the compressed air entering one cylinder and the compressed air entering the next cylinder.

The above and other objects, features and advantages of the present invention will become apparent from the following detailed description taken with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded view of a first preferred embodiment of pneumatic rotary motor according to the present invention;

FIG. 2 is a perspective view of the assembled pneumatic rotary motor;

FIG. 3 is a top plan view in part section of FIG. 2 showing the rotor and the pistons in one position when the pneumatic rotary motor is rotating;

FIG. 4 is a side elevation in part section of FIG. 3;

FIG. 5 is a top plan view in part section of FIG. 2 showing the rotor and the pistons in another position when the pneumatic rotary motor is rotating;

FIG. 6 is a side elevation in part section of FIG. 5; and

FIG. 7 is a top plan view in part section of a second preferred embodiment of pneumatic rotary motor according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1 to 6, a pneumatic rotary motor in accordance with a first preferred embodiment of the present invention is shown. The pneumatic rotary motor comprises a housing 10 including a central, cylindrical channel 11, three cylindrical tunnels 12 equally spaced around a periphery of the channel 11 and in communication therewith, an inlet tube 13 below the tunnels 12 and having the other end connected to a compressed air source (not shown) through a pipe (not shown), an exhaust tube 14 below the inlet tube 13 and having the other end connected to a pipe (not shown) which has an opening exposed to the external, and three ducts 15.

The pneumatic rotary motor further comprises a rotor 20 fitted in the channel 11 and including an eccentric, cylindrical rotation member 21 on a top and having an outer periphery 211, a lower rotating shaft 22 operatively connected to the rotation member 21, an intermediate intake valve 23 adapted to communicate with one end of the inlet tube 13 and one end of the duct 15 or not, and an exhaust valve 24 adapted to communicate with one end of the exhaust tube 14 and one end of the duct 15 or not.

The pneumatic rotary motor further comprises three piston assemblies 30 each mounted in the tunnel 12. The piston assembly 30 comprises a cylinder 31 mounted in an outer portion of the tunnel 12 and being in communication with the other end of the duct 15, the cylinder 31 including a bore 311, a piston 32 slidably mounted in the bore 311 of the cylinder 31 and including an outer periphery 321, a head 322 at one end in contact with the outer periphery 211 of the rotation member 21, and an annular groove 323 in its intermediate portion with a piston ring (not numbered) put thereon, and an outer cylinder head cover 33 threadedly secured to the housing 10 to conceal the piston assembly 30 in the housing 10.

Referring to FIGS. 3 to 6, an operation of the invention will be described in detailed below. It is assumed that compressed air from the compressed air source enters into a space of the cylinder 31 defined by the piston 32 and the cylinder head cover 33 through the inlet tube 13, the intake valve 23, and the duct 15. In one exemplary example of a timing sequence of the pneumatic rotary motor, compressed air enters the three cylinders 31 clockwise sequentially with a phase difference of 120 degrees between two adjacent cylinders 31. The compressed air then pushes the piston 32 inward to cause its head 322 to push (i.e., rotate) the rotation member 21. As an end, power is outputted by the rotating shaft 22. Also, air is released from the first cylinder 31 to the external through the duct 15, the exhaust valve 24, and the exhaust tube 14 at the end of each revolution of the rotor 20. That is, there are an intake cycle, a closed cycle, and an exhaust cycle for each cylinder 31 per revolution of the rotor 20. It is contemplated by the invention that transmission efficiency is greatly increased because connecting rods are not involved. Further, the manufacturing cost is decreased and maintenance is made easy.

Referring to FIG. 7, a pneumatic rotary motor in accordance with a second preferred embodiment of the present invention is shown. The second embodiment is identical to the first embodiment, except that the number of cylinders is five and also the number of pistons is five. The cylinders are arranged like a star.

It is to be understood that the present invention is by no means limited only to the particular constructions herein disclosed and shown in the drawings, but also comprises any modifications or equivalents within the scope of the claims. 

1. A pneumatic rotary motor comprising: a housing including a central, cylindrical channel, a plurality of cylinders equally spaced around a periphery of the channel and in communication therewith, an inlet tube, an exhaust tube, and a plurality of ducts each being in communication with the cylinder; a rotor fitted in the channel and including an eccentric rotation member on a top, a lower rotating shaft operatively connected to the rotation member, an intermediate intake valve adapted to communicate the inlet tube with the duct or not, and an exhaust valve adapted to communicate the exhaust tube with the duct or not; a plurality of pistons each slidably mounted in the cylinder and being in contact with the rotation member; and a plurality of cylinder head covers each releasably secured to an outer portion of the cylinder; whereby sequentially entering compressed air into each of the cylinders through the inlet tube, the intake valve, and the duct will push the piston to rotate the rotation member to output power from the rotating shaft, and release the air from one of the cylinders through the duct, the exhaust valve, and the exhaust tube at the end of each revolution of the rotor.
 2. The pneumatic rotary motor of claim 1, wherein the number of each of the cylinders, the pistons, and the ducts is three.
 3. The pneumatic rotary motor of claim 2, wherein a phase difference of 120 degrees exists between the compressed air entering one cylinder and the compressed air entering the next cylinder.
 4. The pneumatic rotary motor of claim 1, wherein the number of each of the cylinders, the pistons, and the ducts is five.
 5. The pneumatic rotary motor of claim 4, wherein a phase difference of 72 degrees exists between the compressed air entering one cylinder and the compressed air entering the next cylinder. 